Retinal Degeneration in the Guinea Baboon: To extensively investigate retinal degeneration in a colony of guinea baboons as a model for certain types of retinal degeneration seen in man. An inbred colony of guinea baboons is presently being housed at the University of Illinois Medical Research laboratory. The ophthalmic changes (including fluorescein angiograpy) will be closely correlated with the following: 1. Behavioral abnormalities including visual acuity; 2. Electrophysiology; 3. Pathology (light and electron michroscopy); and 4. Biochemistry.